1. Field of the Invention
The present invention relates to headwalls for drain pipes and, more particularly, to sectional headwalls for drain pipes.
2. Description of the Prior Art
The term xe2x80x9cheadwallxe2x80x9d or xe2x80x9cend wallxe2x80x9d typically refers to a reinforced concrete structure that supports one end of a pipe, such as a drain pipe, and retains earth fill on one side of the structure. The usual technique for constructing concrete headwalls involves the manual preparation of forms made typically of wood or metal and built at the intended headwall location. The forms are stripped away from the concrete after the headwall is formed. The forms are temporary in nature and require a significant amount of labor expense for carpentry and other trades necessary for the manual erection of these forms. Several trips to the headwall construction site are generally required before the concrete headwall is complete.
This prior art headwall construction method has other numerous disadvantages. For example, the headwall construction site is often located in an inaccessible or undeveloped area. The wooden forms most often used to construct the concrete headwall are typically made of heavy wooden planks and plywood sections which are nailed together and are difficult, in practice, to erect in these areas. The forms must be stabilized with timbers, boards and stakes that are driven into the ground at the construction site. This can be difficult, time consuming and labor-intensive at undeveloped sites. In addition, paper or another similar material must be positioned around the drain pipe which extends through the forms to prevent concrete seepage and loss when the forms are filled with concrete. There is usually a pronounced gap in the area around the drain pipe because of the paper positioned around the drain pipe while the concrete cures. Furthermore, the forms must be greased to facilitate their removal after the concrete has hardened. Finally, the poured concrete must be vibrated to remove air voids and the surface of the concrete, when hardened, must be smoothed to remove imperfections left by the forms.
Over the years, attempts have been made to improve the xe2x80x9ctraditionalxe2x80x9d prior art method of constructing concrete headwalls discussed hereinabove. For example, U.S. Pat. No. 1,098,766 to Scully et al. discloses a bank retainer for a culvert pipe formed of a plurality of sheet metal plates which are bolted together. In operation, a bottom section of the bank retainer is placed below the culvert pipe and an upper section placed above the culvert pipe. The two sections are then bolted together. Once the sheet metal, box-like structure of the bank retainer is formed, the interior of the bank retainer is filled with earth through an opening in the front of the bank retainer.
U.S. Pat. No. 1,664,503 to Cornell discloses a bulkhead wall for a culvert pipe that includes a series of metal front plates that surround the culvert pipe. The front plates have braces that extend outward into the backfill located behind the bulkhead wall. U.S. Pat. No. 3,779,021 to Green discloses a method of forming a concrete headwall which includes the use of prefabricated forms for concrete. The forms are removable after formation of the concrete headwall.
A more recent attempt to improve the traditional method discussed previously is disclosed by U.S. Pat. No. 4,723,871 to Roscoe. The Roscoe patent discloses a shell-like retainer structure for forming headwalls. The shell-like retainer structure includes two spaced apart plates which each define a U-shaped opening. The plates are centered over a drain pipe with the U-shaped opening defined by the respective plates cooperating with the drain pipe. After the plates are centered over the drain pipe, the structure is filled with earth through an opening formed in the top of the structure.
While each of these references attempts to improve upon the traditional method of forming concrete headwalls, several of the devices disclosed by these references are as heavy, bulky and labor-intensive to use as the concrete forms used in the traditional method. In addition, these devices generally do not provide flexibility in adjusting the height of the headwall. The prior art devices discussed hereinabove typically provide a headwall of a given height which is defined by the height of the device. These devices generally do not provide the ability to alter the height of the headwall in accordance with design parameters for the headwall, such as the terrain at the intended location of the headwall, the amount of backfill that must be retained by the headwall and the size of the drain pipe that is to be used with the headwall. This is a distinct disadvantage because it is common in the art to design the headwall at the construction site without the benefit of engineering the headwall in advance.
Consequently, it is an object of the present invention to provide a headwall that has an adjustable height which may be quickly and easily altered to suit the particular design criteria at the headwall construction site. It is a further object of the present invention to provide a headwall that overcomes the disadvantages of the traditional method of forming concrete headwalls.
The above objects are accomplished with a sectional headwall system made in accordance with the present invention. The sectional headwall system generally includes a unitary base member, at least one unitary sectional member positioned on top of and connected fixedly to the base member and a unitary lid member positioned on top of and connected fixedly to the at least one sectional member. The base member defines an opening extending therethrough and includes two longitudinally extending walls and two headwalls. The base member includes a sleeve extending between the longitudinal walls and defining an aperture extending through the longitudinal walls. The base member further includes a ground engaging edge for engaging the ground. The at least one sectional member defines an opening extending therethrough cooperating with the opening defined by the base member. A drain pipe extends through the aperture defined by the sleeve. In addition, when the base member is in engagement with the ground along the ground engaging edge of the base member, the headwall defines an internal space configured to receive filler material and bounded by the ground, the base member and the at least one sectional member.
The at least one sectional member may include a plurality of male connecting members and the base member may include a plurality of female connecting members. The male connecting members of the at least one sectional member may cooperate with the female connecting members of the base member to connect the at least one sectional member to the base member. The lid member may include a plurality of male connecting members and the at least one sectional member may further include a plurality of female connecting members. The male connecting members of the lid member may cooperate with the female connecting members of the at least one sectional member to connect the lid member to the at least one sectional member.
The sectional headwall system may further include filler material positioned in the internal space defined by the headwall. The filler material may include earth, sand, aggregate and concrete. The drain pipe may be secured to the sleeve of the base member with fasteners. Preferably, at least one of the base member, the at least one sectional member and the lid member has at least one light reflector attached thereto. The base member, the at least one sectional member and the lid member may be made of light absorbing and emitting plastic. A recess may be formed in the lid member and a light reflective delineator bar may be supported in the recess. Furthermore, the base member may further include a frangible cover plate covering the aperture at each of the longitudinal walls of the base member.
In an alternative embodiment of the sectional headwall system according to the present invention, the sleeve extending between the longitudinal walls of the base member may be formed along the ground engaging edge of the base member. The sleeve may define a sleeve opening configured to cooperate with the drain pipe. A method of forming a sectional headwall system is also part of the present invention.
Further details and advantages of the present invention will become apparent in the following detailed description, in conjunction with the drawings wherein like reference numerals designate like parts throughout.